Railroad track lining



Dec. 27, 1960 w. E. KROPP RAILROAD TRACK LINING 6 Sheets-Sheet 1 Filed Nov. 26, 1954 INVENTOR. WILUAM E. KROPP ayflmkbw- ATTORNEY Dec. 27, 1960 w. E. KROPP 2,966,122

RAILROAD TRACK LINING Filed Nov. 26, 1954 6 Sheets-Sheet 2 INVENTOR. WILLIAM E. KROPP BY5 a ATTORNEY Dec. 27, 1960 w. E KROPP RAILROAD TRACK LINING 6 Sheets-Sheet 5 Filed Nov. 26, 1954 INVENTOR.

WILLIAM E. KROPP K5; 4 Ala ATTORNEY Dec. 27, 1960 w, KROPP 2,966,122

RAILROAD TRACK LINING Filed Nov. 26, 1954 e Sheets-Sheet 4 INVENTOR. WILLIAM E. KROPP ATTORN EY Dec. 27, 1960 Filed Nov.

W. E. KROPP RAILROAD TRACK LINING 6 Sheets-Sheet 5 OPERATORS CONTROL LEVER RESERVOIR HYD. CYL,

LEFT

T0 HYD an]? MOUNTED ON BACK PLATE HYD. CYL

RIGHT INVENTOR. WILLIAM E. K ROPP ATTORNEY Dec. 27, 1960 w, KRQPP 2,966,122

RAILROAD TRACK LINING 6 Sheets-Sheet 6 Filed Nov. 26, 1954 INV EN TOR WILLIAM E.KROPP mwuuo ATTORNEY United States Patent O RAILROAD TRACK LINING William E. Krupp, 847 N. 18th St, Allentown, Pa.

Filed Nov. 26, 1954, Ser- N6. 471,355

12 Claims. c1. 104-3 My invention is a machine for lining railroad track.

The aims of my invention are to make it possible to carry out this operation quickly and efficiently, with a minimum of manpower and hand labor, with a machine that can be quickly removed from the right of way to permit the passage of trains and then quickly replaced to resume the lining operation. Other purposes and advantages will be apparent from the following description and specification.

Rail is ordinarily spiked to ties, which are embedded in loose rock or other ballast. The two rails, being fastened rigidly to transverse ties, are thus secured in a parallel position near the desired tolerances relative to each other. However, misalignment of the rail-andtie assembly in a longitudinal direction may and does occur. Such misalignment may range from a fraction of an inch to several inches, and involve the displacement in a transverse direction of a number of ties. Misalignment results, for example, from use, minor errors in laying track, and cleaning, replacing, or raising ballast.

A number of mechanical devices have been developed for lining track, but the general practice still is to realign track by hand labor. This requires the eflfort of as many as twelve men, who insert levers under the rails to pry the entire track assembly (ties, rails, and joining means) over on the ballast; another employe by sighting along the rails directs the degree of movement necessary to straighten the track.

The principal purpose of my invention is to provide mechanical means to accomplish the physical movement of track which may be operated by a single man and save a great deal of labor in the realignment operation. Another purpose of my invention is to provide a direct lateral thrust against the rail, as distinguished from the lever-ing action by which the work is presently performed, which involves an upward or lifting component. A further purpose of my invention is to provide a constant lateral thrust through the entire operation for such distance as is necessary to align the tracks as distinguished from the operation as it is presently performed, which frequently involves the taking of several bites at the work which may not correspond with the exact degree of movement necessary for desired alignment. A further purpose of my invention is to secure a firm base in the ballast supporting the rails and ties from which to exert a lateral thrust against the rails to properly align the latter. Further purposes and functions of my invention will appear from the following.

In the drawings:

Fig. 1 is a plan view of the track lining machine.

Fig. 2 shows the front elevation of the track lining machine.

Fig. 3 shows a side elevation of the track lining machine.

Fig. 4 shows a cross section view of the anchoring means. a

Fig. 5 is a fragmentary plan view of the upper trunnion showing the connection between hydraulic cylinders 'ice and the anchoring means, which are shown in cross section.

Fig. 6 shows the lower trunnion mounting the anchoring means, shown in cross section, and the hydraulic cylinders actuating the railengaging means.

Figs. 7 and 8 show a plan and a side elevation respectively of a standard tractor used in track Work, with mounting means for the track lining machine.

Fig. 9 is a schematic diagram showing hydraulic lines and controls for the power-operated elements of the track lining machine.

Figs. 10, l1, and 12 'show front elevations of the track lining machine in relation to railroad track in three positions preparatory to lining track.

Fig. 13 shows a plan view of the track lining machine mounted on a tractor in position with respect to railroad track in which the lining operation is performed.

Briefly, the track lining machine operates by the exertion of constant pressure upon a rail engaging member to move the track assembly (track, ties and spikes) in the direction desired, with anchoring means inserted into the ballast between the rails to hold the machine in place against the reaction to such pressure. The anchoring means is rotatable to permit a substantial penetration of its lower end into the ballast underlying the track assembly and also pivotable to position the anchoring means in an angular relationship to the ballast bed such that exertion of a lateral force thereagainst will result in a firmer embedding of the anchoring means in the ballast. The anchoring means may be pivoted to such angular relationship prior to penetration of the ballast or (as in the operation fully described hereafter) after such penetration. 1

In more detail, the specific embodimentof my invention shown in the attached drawings Figs. 1, 2, 3 and 4, consists of two side plates 1 rigidly fastened in spaced relation to each other by foot plates 2. The anchoring means are slidably mounted in a cylindrical guide 4 afiixed to a trunnion 3 (to be more fully described) pivoted on the side plates 1. Referring to Figure 3, a keyway 6 in casing 5 and a corresponding key (not shown) in guide 4 prevent rotation of the casing relative to the guide.

The anchoring assembly as shown in Fig. 4 consists of the cylindrical casing 5 within which drive shaft 7. is rotatably mounted on bushings 8. The drive shaft drives a digging head 9, the extreme diameter of which may be the same as the casing 5 so as to permit the casing more easily to follow the digging head into the ballast. The drive shaft is rotated by a motor, shown as hydraulic motor 10 through a standard vertical shaft gear reducer 11, the drive shaft 12 of which connects with the main drive shaft 7. Lubrication is provided by drip oiler 13. The motor and gear reducer are mounted on the anchor casing 5 by a flange 14 and compositely constructed mounting plate 15. Further rigidity in this assembly is provided by bracket 16. The lower ends of a pair of double directional hydraulic cylinders 17 are pivotally mounted on the outside of each side plate 1 in parallel relationship to the anchoring means by mounting brackets 18. The upwardly extending piston rods of cylinders 17 are fastened to the anchor assembly at flange 14. Cylinders 17 provide a vertical thrust in either direction to raise or lower the entire anchoring assembly sliding in guide 4.

A pair of double directional hydraulic cylinders 19 (more clearly shown in Fig. 2) are pivotally attached to the guide 4 of the anchoring assembly by a trunnion 21. The piston rods of cylinders 19 are pivotally atfixed to side plates 1 by pins 20. Actuation of the piston rods in cylinders 19 result in transverse pivoting or rotation of guide 4 and hence of the entire anchoring assembly on the trunnion 3 relative to the side plates, so that the anchoring assembly may be given a vertical position or an angular position in either direction relative to the track bed. The importance of this power adjustment will be apparent from the operation of my invention to be described.

Rail engaging feet 24 are pivotally mounted at opposite ends of the side plates 1. At each end, a foot 24 is aflixed to an arm 23 which is swiugably mounted on the side plates by pin 22. The foot 24, which engages the foot of the rail, may be flanged at the bottom to prevent the foot from slipping up, as in the embodiment shown in the drawings, but the flange may be omitted when the foot 24 is extended downwardly to a point that its end does not reach the foot of the rail in the lining operation. Double directional hydraulic cylinders 25 are mounted on the trunnion 3 by pins 33 and their piston rods are each pivotally connected to one of the arms 23 by a pin 26.

As shown in Figs. 7 and 8, the entire track lining machine described above may be mounted on a standard tractor 31 used in track work, though the track lining machine may be mounted on any movable car, as with flanged wheels for movement on the rails, as may be desired. Such tractors may be operated on the ties between the rails, and have the advantage over other track working machinery that they may be quickly removed from the tracks to permit the passage of trains, and the additional advantage over flanged wheel vehicles moving on the rails that the former leave the rail heads unobstructed for sighting alignment. Such tractors may be equipped with motors controlled by the tractor operator to provide hydraulic power to actuate all the moving parts of my invention requiring power in the aligning operation. A further advantage to attaching my inven 'tion to such track working machinery is that the tractor provides further stability for the aligning machine in a vertical direction. The track lining apparatus is not so rigidly attached to the tractor, however, that the tractor may not move laterally with the tracks as they are realigned.

The tractor mounting is shown in Figs. 1, 7, and 8. Compositely constructed mounting assembly 27 fixed on a side plate 1 is provided with a cross bar terminating in members adapted to slide in channels provided in compositely constructed mounting assembly 28. Mounting assembly 28 may be mounted on a tractor or other vehicle, and affords a channel for the sliding members of mounting assembly 27. Double directional hydraulic cylinders 29 (see Fig. 3) are pivotally mounted at their upper ends on the upper part of mounting assembly 28 and their piston rods are pivotally mounted on the rear side plate 1, and serve to raise and lower the entire track lining assembly. Guide arms 30 are adjustably pivotally mounted on plate 1 at one end and on the tractor at the other, and, in conjunction with the sliding engagement between mounting assemblies 27 and 28, prevent the action of the rams 29 in raising and lowering the track lining assembly from pushing the latter out of the desired line of vertical movement. Figs. 7 and 8 show mounting assembly 28, which is welded in place on the frame of tractor 31 and further provided with braces 32 fastened to the tractor frame and to the upper part of mounting assembly 28.

Fig. shows details of trunnion 21, in position between plates 1. Guide 4, casing 5, and drive shaft 7 of the anchoring means are shown in cross section.

Details of trunnion 3 are shown in Fig. 6. Trunnion 3 is provided-with round bosses 3A rotatably fitted into round holes in plates 1 to provide the pivotal bearing for trunnion 3. Cylinders 25 are pivotally mounted on trunnion 3 by pins 33. Brackets 18 have pins 34 welded in place. The brackets 18 are bolted to side plates 1. The pins 34 are movably fitted into holes provided '4 bosses 3A in trunnion 3, and constitute the pivotal mounting for hydraulic cylinders 17.

Hydraulic power and controls Fig. 9 schematically shows the method of providing hydraulic power and controls for the track lining apparatus, including reservoir 36. From the reservoir, delivery pipe 37 leads to pump 38, which provides hydraulic pressure through conduit 39 and manually operated valve 40 for hydraulic motor 10. Flexible conduits 41 and 42 deliver hydraulic fluid under pressure to motor 10 and return conduit 43 provides for the return of hydraulic fluid through T coupling 44 and return conduit 45 to the reservoir. Return conduit 46 provides for the return of hydraulic fluid from valve 40 to the reservoir. It is to be understood that valve 40 is a hand operated valve of a suitable type by which hydraulic fluid under pressure may be selectively diverted through conduits 41 or 42 to the motor 19 to provide for the rotation of the motor 10 in either direction (in either case fluid returning to the reservoir through conduit 43 as described); or (when the valve is in the neutral position) for the return of fluid through conduit 46 to the reservoir 36 to provide for idling of pump 38.

Delivery pipe 47 connects the reservoir with pump 48 which provides power for the various hydraulic cylinders in the track lining apparatus in the following manner: Delivery conduit 49 delivers 'fluid under pressure through the hydraulic cylinder control valves to be described, and conduit 45 returns the fluid to the reservoir when the control valves are in neutral position to provide for idling of pump 48.

Two independent manually operated control valves 50 control the operation of the rail moving hydraulic cylinders 25 through conduits 51 and 52'which are connected to ports at opposite ends of the rail moving cylinders 25, control valves 50 being of a suitable type by which fluid under pressure may be delivered selectively through conduits 51 or 52, to opposite ends of rail moving cylinder 25 to actuate hydraulic cylinders 25 selectively in the rail pushing operation or in withdrawing the piston of hydraulic cylinder 25 to its neutral position, the other conduits in each case serving for the return of fluid to the valve system and thence through conduit 45 to the reservoir.

Manually operated control valve 53 operates hydraulic cylinders 19, and may selectively deliver fluid under pressure, on the one hand through conduit 54, T coupling 55, and conduits 56, through ports at the right-hand ends of hydraulic cylinders 19, to exert pressure by the pistons of cylinders 19 on the upper end of the anchor assembly, moving it to the left; or, on the other hand, through conduit57, T coupling 58, and conduits 59, through ports at the left-hand ends of hydraulic cylinders 19, to exert pressure by the pistons of cylinders 19 to move the upper part of the anchoring assembly to the right.

Manually operated control valve 60 selectively delivers fluid under pressure, on the one hand, through conduit 61, T coupling 62, and conduits 63 to the upper ends of hydraulic cylinders 17 to drive the anchoring assembly down into the ballast; or, on the other hand, through conduit 64, T coupling 65, and conduits 66' to the lower ends of hydraulic cylinders 17 to raise the anchoring assembly. 4

Manually operated control valve 67 selectively delivers fluid under pressure, on the one hand, through conduit 68, T coupling 69, and conduits 70 to the lower ends of hydraulic cylinders 29 to raise the entire track lining assembly; or, on the other hand, through conduit 71, T coupling 72, and conduits 73 to the upper ends of hydraulic cylinders 29 to lower the track lining apparatus to operating position.

In each of the above cases, when one set of conduits is selected by means of valves 53, 60 or 67, the others is provide for the return of fluid from the cylinders'to the valve system and thence through conduit 45 to the reservoir 36.

Details of construction of the elements of the hydraulic system (e.g., pumps, valves, motor, and cylinders) are not shown as these are standard items of equipment and are well known.

Operation The operations of the controls are clear from the above description, and the operation of the track liner will be described in terms of its mechanical functions.

The tractor is moved along the tracks between the rails with the track lining assembly in raised position. Fig. 10 illustrates the relative positions of the track lining assembly, the tractor, and the track structure. At the point where it is desired to line the tracks, the track lining machine is placed in position, with the lining assembly as shown in Figs. 10 and 13, and the lining assembly is lowered by actuating hydraulic cylinders 29 into a crib" (enclosed between the rails and two ties) so that foot plates 2 rest on the ballast. The digging head 9 is rotated and the cylindrical casing of the anchoring assembly is driven down into the ballast by hydraulic cylinders 17 until suificient depth has been attained to firmly anchor the track liner. Fig. 11 shows the relative positions at this point, with the track lining assembly lowered onto the ballast and the anchoring device with cylindrical casing 5 driven into the ballast. The track may be aligned now in either direction by actuating one of the hydraulic cylinders 25. However it may be desirable before this and depending on the circumstances to actuate one of the hydraulic cylinders 19 so as to pivot the anchoring assembly on trunnion 3, moving the top of the anchoring assembly in the direction in which it is desired to move the track. Fig. 12 shows the anchoring assembly thus pivoted on trunnion 3 and the resulting change of position of the track lining assembly (to be compared with the position shown in Fig. 11) into contact with the rail against which the force is to be exerted through foot 24. In addition, the anchoring assembly thus forms an included acute angle with the direction of force applied to the rail. The advantages of this operation are: that the casing 5 of the anchoring assembly is thus placed at an angle so that there is a downward component in the reaction to the thrust against the rail which tends to confirm the seating in the ballast of the anchoring assembly; that the entire track lining machine may be moved in this manner in the direction of the rail to be pushed; that the operation solidifies ballast in the tie crib giving positive resistance to pressure required to move the track; that the foot plates 2 may be more firmly seated on the ballast; and that the appropriate foot 24 of the rail contact means may be brought in direct contact with the foot of the rail without actuating the hydraulic cylinder 25, which thus permits the use of the full range of the hydraulic cylinders 25 in the lining operation itself and so permits a further structural advantage in broadening the practicable tolerance between, on the one hand, the distance between the feet 24 of the rail engaging means in their withdrawn position, and, on the other hand, the distance between the feet of the rail.

At this point in the operation, by actuation of the ap propriate hydraulic cylinder 25 to exert pressure through the foot 24 of the rail engaging means on the foot of the rail, the rail assembly may be moved laterally to the desired position, and can be displaced at will much further than is usually required by normal rail alignment problems. In many instances it is unnecessary to actuate cylinder 25 .and foot 24 when the rail may be moved the desired distance by continuing the pivotal movement of the anchoring assembly on trunnion 3 after foot 24 has been brought in contact with the rail in the movement of the track lining assembly as above described.

After theliiiing operation, the rail engaging means 25 is withdrawn from its extended position by reversing the appropriate hydraulic cylinder 25, the anchoring assembly is returned to a vertical position by hydraulic cylinders 19, the casing 5 is raised from the ballast by hydraulic cylinders 17, and the entire track lining assembly raised from the crib by hydraulic cylinders 29 to an elevation appropriate for moving to a new work location. While I have described a present preferred embodi-' ment of my invention, it may be otherwise embodied within the scope of the following claims.

Having thus described my invention, I claim:

1. A track lining machine mounted on a vehicle movable along railway track and operable to slide the track horizontally over a foundation supporting the track; comprising an elongated vertical shaft mounted for rotatable movement about its longitudinal axis, said shaft being rotatably mounted in a guide aflixed to said machine; power means mounted on the machine and operatively connected to the shaft to move the shaft vertically relative to the machine and foundation; second power means mounted on the machine and operatively connected to the shaft to rotate the shaft about its longitudinal axis; the vertical and rotational movement being effected simultaneously to embed the shaft in the foundation; thrust means connected to and extending transversely of said machine to exert a horizontal thrust on one of the rails to slide the rails and connecting ties horizontally over the supporting foundation; the embedded shaft providing a stationary base from which said horizontal thrust is applied against said one rail.

2. A machine as described in claim 1 wherein said thrust means are extensible power members pivotaliy mounted on said guide, each of the power members being extensible substantially horizontally to exert a force against one of said rails.

3. A track lining machine mounted on a vehic1e'mov able along railway track and operable to move the track horizontally over a foundation supporting the track; comprising an elongated vertical shaft mounted for rotatable movement about its longitudinal axis, said shaft being so mounted in a guide aflixed to said machine; said guide being pivotally mounted on said machine to pivot the guide and shaft transversely of the machine and the longitudinal axis of the rails; power means mounted on the machine and operatively connected to the shaft to pivot said guide and shaft in said transverse direction; power means mounted on the machine and operatively connected to the shaft to move the shaft vertically relative to the machine and said foundation; power means mounted on the machine and operatively connected to the shaft to rotate the shaft about its longitudinal axis; said vertical and rotational movement being effected to embed the shaft in said foundation; horizontal thrust means connected to and extending transversely from said machine to exert a horizontal thrust on one of the rails to move the rails and ties horizontally relative to the supporting foundation; the embedded shaft providing a solid base from which the horizontal thrust may be applied against said rail.

4. A machine as recited in claim 3 wherein said means to pivot the guide and shaft are extensible power members which pivot the shaft to form an included acute angle between a portion of the shaft not embedded in the foundation and the direction of horizontal thrust by said thrust means. i

'5. A track lining machine mounted on a vehicle movable along railway tracks and operable to slide rails and ties horizontally over a foundation for the tracks, comprising an elongated vertical shaft movable vertically in a mounting rigidly affixed to said machine; means operatively afiixed to the machine and shaft to move the shaft vertically relative to the machine to embed the shaft in said foundation thereby providing a base from which a horizontal thrust may be exerted against one of the rails; side thrust members connected to and extending transversely of said machine to exert a horizontal thrust on one of said rails to move the rails horizontally over the foundation; and means mounted on the machine and operatively connected to said shaft to pivot the shaft transversely of the machine and the longtiudinal axis of the rails in a substantially vertical plane. Y

6. -A machine according to claim wherein the shaft is pivotal transversely of the machine about a horizontally extending axis afiixed to the machine; the axis, the thrust members and the rails being located in substantially the same horizontal plane.

7. A track lining machine including a wheel-mounted vehicle movable along railway track, an anchoring assembly affixed to the vehicle; said assembly including a guide pivotally mounted on the vehicle, said guide being pivotalsidewise in a vertical plane extending transversely of the track, an elongated vertical drive shaft mounted in said guide, said shaft being rotatable about its longitudinal axis and slidable vertically within the guide, a digging head integral with the lower end of the drive shaft and projecting below the guide, power means connected between the vehicle and shaft to slide the shaft vertically downward through the guide to permit the shaft and digging head to penetrate material underlying the track and to subsequently withdraw said shaft and digging head from said material; second power means operatively affixed to thedrive shaft to rotate the drive shaft and digging head about its longitudinal axis to displace said underlying material during the vertical downward movement; and thirdpower means connected between the vehicle and shaft to selectively position and pivot said shaft and guide sidewise in a vertical plane; and extensible power means movably affixed to said guide and located within said vertical plane, a foot integral with the outermost transverse point of said extensible power means, said foot being engageable with one of the rails of said track to exert a transverse force on said rail when the last mentioned power means is extended.

, 8. A track lining machine mounted on a vehicle movable along railway tracks and operable to slide rails and ties horizontally over a foundation for the tracks comprising a cylindrical guide pivotally mounted on the vehicle with its longitudinal axis normally vertical but pivotal transversely of the vehicle; an elongated vertical shaft slidable vertically in and pivotal with said guide; a piston and cylinder operatively connected between said machine and said shaft to move the shaft upward and downward within and relative to said guide; a portion of the shaft being embedded in the foundation a substantial distance when the shaft is in said downward position; a second piston and cylinder operatively connected between said vehicle and said guide to pivot said guide and shaft in a vertical plane extending transversely relative to the vehicle and traeks.

9. A machine for aligning railway track by sliding the rails and connecting ties over a foundation for the track including a vehicle movable along the rails; a lining apparatus affixed to one end of the vehicle, said apparatus being movable vertically relative to the vehicle from a raised position to a lowered position on the foundation for the track; power means affixed between said vehicle and lining apparatus to move the apparatus vertically; said lining apparatus including a frame, a cylindrical guide affixed to the frame, an elongated hollow casing slidably mounted in the guide, a shaft rotatably mounted within the hollow casing and the lower end of the shaft extending out of the lower end of the casing; a digging head integral with the lower end of the shaft; the longitudinal axes of the guide, casing and shaft being vertical; a piston and cylinder having one of its ends afiixed to said frame and the other of its ends affixed to said cas- 8 ing such that the piston and cylinder move the casing and; shaft vertically relative to said frame; a motor integral with the casing and operatively connected to said shaft to rotate the shaft inside the casing during said vertical movement of the shaft; a second piston and cylinder having one of its ends affixed to the lower end of said guide and the other of its ends movably suspended from said frame, said second piston and cylinder extending from the guide toward one of the rails; a foot integral with said other end of the second piston and cylinder and engageable with one of the rails to exert a transverse force thereon sufficient to move the rails and ties slidably over the foundation; said shaft being embedded in the track foundation during the operation of the transverse force and providing a stationary base from which the transverse force may be exerted; and power generating means to supply pressurized fluid to said motor and said cylinders.

10. A machine as recited in claim 9 wherein said guide is pivotally mounted at its lower end on a horizontal axis integrally aflixed to said frame; said guide, casing and shaft being pivotal in a substantially vertical plane extending transverse to the longitudinal axis of the rails; a third piston and cylinder having one of its ends affixed to the frame and the other of its ends affixed to the upper end of the guide such that upon activation of the third piston and cylinder the guide, casing and shaft are pivoted in said vertical plane.

11. A railway track lining machine for sliding rails and connecting ties over the foundation for the track including a pair of vertical plates spaced from each other and extendingtransversely of said rails, a horizontal foot plate atfixed to the bottom of said vertical plates and spanning the space between the plates to maintain the plates stationary relative to each other; 'a guide located between and aflixed'to said vertical plates, the longitudinal axis of the guide being vertical; an elongated vertical shaft slidably mounted in said guide; a first power means operatively connected to and between said plates and the shaft; said first power means being operable to move the shaft from an elevated position to a lowered position in which the shaft is embedded in said foundation; second power means to rotate the vertical shaft about its longitudinal axis during movement from said elevated position to the lowered position such that a portion of the foundation is displaced to permit penetration of the shaft into the foundation; an arm mounted on said plates and swingable between the plates, a rail engaging foot afiixed to the lower end of the arm in the proximity of the rail to be aligned; third power means affixed to the plates and said arm to move the foot and arm transversely into engagement with and exert a transverse force upon the rail; the embedded shaft providing a stationary base from which said transverse force may be exerted.

12. A machine as recited in claim 11 wherein said guide is pivotally mounted on an axle affixed to and between said plates; said axle being substantially located in a horizontal plane passing through the longitudinal axes of the rails; and fourth power means operatively connected to and between said plates and said guide to pivot the guide and shaft transversely of the longitudinal axes of the rails.

References Cited in the file of this patent UNITED STATES PATENTS 1,458,402 Forsberg June 12, 1923 1,592,153 Peterson July 13, 1926 2,048,072 Johansen July 21, 1936 2,693,769 Herlehy Nov. 9, 19.54 2,705,378 Wendt Apr. 5, 1955 2,861,521 Vito et al Nov. 25, 1958 

